Automatic shutoff



Nov. 2, 1943. s. w. GRAHAM 2,333,370

AUTOMATIC SHUTOFYF Filed Sept. 16, 1940 2 Sheets-Sheet 1 INSULATIOlrromvsv.

Nov. 2, 1943. s. w, GRAHAM 2,333,370

AUTOMATIC SHUTOFF Filed Sept. 16, 1940 2 Sheets-Sheet 2 IN VENTOR.

Siarzlqyhz Graham BY JW 14 Tram/E y.

Patented Nov. 2, 1943 UNITED STATES PATENT OFFICE AUTOMATIC SHUTOFFStanley W. Graham, Los Angeles, Calif.

Application September 16, 1940, Serial No. 356,903

4 Claims. (01. 742) My invention relates to an automatic shutoff, andmore particularly to an automatic shutoff for internal combustionengines.

In Diesel engines, the cracking up Of babbitt is not accompanied by aclearly perceptible knocking that signals to the operator that somethingis wrong. Thus it is possible for the babbitt to break up to the pointwhere the connecting rod bearing of a. Diesel engine becomes overheatedand worn, and damages the crank haft, without the operator knowing ofit.

vAn object of the present invention is to provide means forautomatically shutting off the Diesel engine when the babbitt has worndown to a point where the connecting rod bearing begins to overheat.Thus the Diesel engine is stopped before the bearing burns out andbefore any damage is done to the crank pin on the crank shaft. Aninjured crank shaft is of course rather expensive to replace, and it isto avoid such expense that is an object of the present invention.

My invention also has for its objects to provide positiveness inoperation, economy of manufacture, greater speed of operation, generalsuperiority in serviceability, relative simplicity, inexpensiveness inconstruction, and greater general efiiciency.

The invention also comprises novel details of construction and. novelcombinations and arrangements of parts, which will more full appear inthe course of the following description. However, the drawings merelyshow and the following description merely describes one embodiment ofthe present invention, which is given by way of illustration or exampleonly.

In the drawings, like reference characters designate similar parts inthe several views.

Figure 1 is a broken, vertical section through an embodiment Of minvention.

Figure 2 is a section taken on the line 22 of Figure 1.

Figure 3 is a perspective view of a mercury switch arm comprised in theinvention.

Figure 4 is a view similar to Figure 1, but showing a modifiedconstruction.

Figure 5 is a section taken on the off-set line 55 of Figure 4.

Figures 6 and 7 are perspective views of details comprised in theembodiment, which will hereinafter be more fully described.

Referrin more in detail to the drawings, the reference numeral 5designates a broken-away portion of a connecting rod bearing, to which aplate .6 has been screwed, as shown at The plate 6 is curved similarlyto the curvature of the bearing 5.

A resilient contact 8 is riveted at one end to the plate 6, as suggestedat 9. The opposite end of the contact 8 is bent and held under tensionagainst the side of the plate 6, by means of fusible solder Ill. Thesolder I0 is preferably, although of course not necessarily, fusible at300 F. which is suflicient under ordinary working conditions, but iswell below the melting temperature of the bearing 5, in case it issubjected to excessive cracking. When the contact 8 is thus soldered tothe plate 6, the contact is bent to conform with the curvature of theplate 6. When the connect ng rod becomes overheated by reason of thebabbitt |2 becoming overheated, the heat causes the solder I0 to melt,permitting the resilience of the contact 8 to move such contact to theposition shown by broken lines I3.

Another contact M in the circuit has a curved contact face l5. When thecontact 8 is soldered in position upon the plate 6, there is noengagement between the contacts 8 and H, but when the solder I0 ismelted, the contact 8 springs outwardly so that it engages the contact Min the rotation of the bearing 5.

The contact I4 is adjustably fastened on an arm l6. whi h in turn isheld on a bracket I! that is insulated from housing l8 of the apparatus.A wire I9 connects the arm I 6 and contact M in the circuit. The bearing5 and the contact 8 are grounded through the frame of the engine, toinclude the contact 8 in the circuit.

A housing for the mechanism for shutting off the engine is suggested at2|. Depending from the housing 2| is a fuel line22 for feeding fuel tothe eng ne. A tapered valve 23 engages opposed seats 24 to shut off thefuel line 22. Aneedle valve may be used for the gate valve 23.

A vertical operating bar 25 controls the shutoff valve 23. Brackets 26and 21 provide guides for sliding bar 28, which is pinned to bar 25 andeffects vertical motion of the latter bar.

A lever arm 29, fulcrumed on the shaft 30, is pivotally connected to thebar 28 at 3|. The shaft 3!] is mounted in brackets 44, 45. The outer endof the lever 29 carries a mercury switch 32. Wires 33 and 34 connectwith contacts 35 and 36 in the tube 32. Clamps 31 maintain the mercurytube on the lever 29. A knob 38 exteriorly of the housing 2| is mountedon a rod 39 that connects with the outer end of the lever 29, at thepoint 40.

I A coiled spring 4| is connected with an adjustinoperative.

ing screw 42 in the housing 2|. The spring 4| tends to pull the leverarm 29 downward. A crank handle 43 is fastened on the outer end of theshaft 30, to aid in re-setting the mercury switch and in re-setting thevalve.

A solenoid or electromagnet 46 controls a core member 41, which isslidable in a sleeve 43. A coil spring 49 is disposed behind the coremember 41. The core member 41 has a pointed end 50 to e age. in anotch5| ins-the slidingbar 28.

A wire 52, connects with a grounded; source of electrical energy (notshown). Wire 52 connects with one end of the winding of the solenoid 46,while the wire 34 connects with the opposite end of the solenoidwinding. Wires |-9-and 33 connect with a wire 53, and a wire 54.connects. with a ground 90. A manual switch 55 is arranged to make andbreak thecircuit throughtho wires 53 and 54, to permit periodic testing,

In the modified form shown in Sheet II, a plate 5.1 having: notchesv 58is: substitutediorthe plate 6. Contact 8 in Sheet II is not only held;down by solder-1 .11%. also y" a 01in 59; whosexben ends-6Q: aredisposed. inwthe notches 59., The clip is. also'soldereda in position;as-denoted by: dots in Figure The; bent endsrvflt are; firmlyanchoredgin thevnotches: 58by solder; V

' One side, Of, housing- 6.-|-:, in: the modified. construction,supporta a 'pivot. 62, which pivotally supports. airocker 33..Depending-fromtherocker 53 is a finger 6.4-=ha-ving a hooked-end 65.

The. hook. 65 engages: a pin 66 on a core61= of a solenoid 58. The,- end-69 of'the. core 61- is bifurcated to receive the hook-55.

- A bar lo-of the-rocker 63/ supports aclosed tube 1|, containingabodyof mercury. 12.. Straps" .13 hold. thezmercury tube on the bar 10.

1 An over-center,snap-acting spring 14. .connects an end 15 of thebar;10- with a bracket .16 on. an opposed wall of the housing. The; rockerisv arranged: for the-spring tosnap the spring, to one-side ortheother-of the pivot 62, to provide a quick makeor-break of thecircuit.

.A. link- 11- connects. the bar. 25.with arm. 15 of the bar 10. The link.11. provides abutments 18 the solenoid 6,8. A. manual switch, is,arranged to ground the circuit manually for testing the authe notch 5|in the bar 28. The spring 4| thereupon swings the lever 29 downwardly,as these parts are shown in Figure 1. This movement of even though thebearing 5 stops in a position in tomati'c unitiin th'ebox, orhousing2|-.,."Wire 8.6

connects'the solenoid-to a suitable source of electrical-energy (not;shown.)

uring the ordinary operation of the engine, the connecting rod bearing 5is at atemperature below the'meltil'ig poin-t'of'thesolder l0.During'th-is normal operation of the-engine, the contacts 8 and H areout of engagement with each other, so thatfth'e present apparatus isrendered *When the babbitt f2 overheats from any cause to the pointwhere itneeds to be replaced, bearing 5 becomes overheated, thusraising" its. temfperature' aboyelthe. melting point otthe solder-l0.

bearing; 5-, the; contacts Bwand; l4 engage each other, thus energizingthe solenoid 49.. .The core 41- is thereby withdrawn from engagement.with which the contacts 8 and I4 are in engagement with: each other.

The mechanism is reset by re-soldering the contact 8 to its full lineposition, and raising the le- V3129; toitsposltionshown in the drawings,by means of the knob 38 and/or the crank arm 43. When the bar 28 israised, the spring 49 urges the: iron .core; 4.1. intdengagement with.the notch 5.| ofthebar 28'. Theme-mung .60. .has again closed thesolenoid circuit, so that, the solenoid may be energized as soon as thecontacts 8. and I4. again; engage each other. Raising ,ofcth e bar28-again opens-the fuel line22. I

a For the normal operation. ofthe modifiedconstructiomthe manuaijswitch-85 opened. The spring contact. 8, operatesin the modifiedconstructionthe. same, as'heretofore described, except that the clip 59 aids. in.maintaining, the spring, contact in thelfullline position shown inFigure, 4, until the. solder is. fused.

When thes'older melts: and the. contact springs to the broken lineposition 13, the circuit of the solenoid is closed. sincethe normalpositionof, the

mercury switch-is as shown in Figure .4. Closing.

said circuit energizes the solenoid, whereby. its core 61 is drawn to,the rightin said. figure. movement, of thecore. rocks the, rocker 5.3 sothat the finger 6 4, is movedto its broken. line, position. This.movement of the rocker 63. closes the valve 2am the fuel line. Thespring. 14; causes the valve to snap toits closed' position. At the.same time/the mercury switch is tipped, causing the mercury to flow awayfrom the contacts..32,,.94, so as to break the solenoid circuit. Themercury switch and valve. arere-setby means of the, handle after thebabbitt, in the bearing is repaired and after the contact 8 is re-set.Thespring 14 tends tohold the mercury switch inthis re-set position,which is the position shown inthe drawings. The spring 14' also tends tomaintain the valve 23 in an open position.

While I have illustrated and described what I now regard' as thepreferred embodiment of my invention; the construction is, of course.subject to modifications without departing from the spirit and scope oi'my invention. I, therefore, d'o-not wish to restrict-myself to theparticular form of construction illustrated and described, but desire toavail myself ofall modifications which may fall within the scope of theappended claims.

Having thus my-invention, what I claim and desire to secure by LettersPatent is:

1. In a device for controlling; operation of an engine having anorbitally moving connecting rod bearing subject to excessive heattherein, orbitally moving rotary means having a curved outer, surface,means comprising atilat spring secured under tension in arcuate form onsaid curved-surface, a part of-said spring being movtension of saidspring in response to heat of predetermined degree transmitted to saidrotary means from said bearing.

2. In a, device for controlling the operation of an engine, a partadapted to move orbitally, said part having a curved outer surface, aspring which when not under tension is flat with its flexing surfaces inparallel planes, said spring being secured near one of its ends to thecurved outer surface of said first-mentioned part by means resistant tothe abnormally excessive heat, and its other end being secured to saidlastmentioned curved surface by means resistant to normal temperaturesof said engine but fusible under abnormally excessive heat so when fusedto release the end of said spring.

3. In a device for controlling the operation of an engine having a partwith a curved exterior surface subject to excessive heat, meanscomprising a flat spring secured by means resistant to such excessiveheat at one of its ends to the curved surface of said first-mentionedpart, said spring being flexed in arcuate form to provide tension andsecured on said curved surface at its other end by means fusible by suchexcessive heat, said flat spring being adapted upon the fusing of saidlast-mentioned means and release of its tension to assume a positionparallel with a chord of the surface of the part to which it isattached.

4. In a device for controlling the operation of an engine, a rotatablepart subject to excessive heat during abnormal operation of said engine,said part being enclosed within a member having a curved exteriorsurface, means comprising a fiat spring of long rectangular form which,when not under tension, will retain its flexing surfaces in parallelplanes, said spring being secured by means resistant to such excessiveheat, adjacent one of its ends, to the exteriorly curved surface of saidmember, means adjacent the other end of said spring to secure it undertension in arcurate form on said curved exterior surface of saidrotatable member, said last-mentioned means being fusible under suchexcessive heat and adapted when in fused condition to release saidspring from its arcuate tensioned position, and means adapted to contactwith the free end of said spring when said spring is not under tension.

STANLEY W. GRAHAM.

